I believe some are already in the works. There's an old thread around here somewhere...
Once I get my hands on the FPGA Arcade I intend to put together a hard file with a Classic Workbench install and then add as many emulators to that as I can find. Some off the top of my head:
VICE: 8bit Coomodores (C64, VIC20, PET, etc)
MAME: Arcade classics!
BBC model B: I have the floppy somewhere, hope it works.
Spectrum: For those who want to play C64 games only with wank graphics and crap sound. 
PC Task: MS DOS and Windows 3.x or even Windows 95?
Shape Shifter: I also have the MacOS7.x package that Cammy & friend assembled.
It will do until some "native" cores appear. Can anyone think of any more?
good idea, i would like it more as a gaming device, so 8/16-bit consoles as well as Amiga, C64, arcade etc
that would only be feasable with supported cores for the replay board though
